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Sea ice

Schematic representation of an hypothetical sea ice dynamics scenario show ing some of 

the most common sea ice features. In this scenario, a relatively undisturbed cover of f irst-year sea ice is pushed against much thicker ice (a multiyear ice floe), thereby generating a

pressure ridge. Tightly packed smaller f loes betw een the fast ice and the multiyear floeoriginate from previous events. A lead forms w ithin the expanse of first year ice, perhaps

resulting from a shift in w ind direction. The bear provides an approximate vertical scale for the ice features in this scenario (the horizontal scale is not respected in this sketch e.g. the

fast ice zone typically extends much further offshore).

Sea ice topography - this example is from the Beaufort Sea, off the nor thern coast of 

 Alaska.

From Wikipedia, the free encyclopedia

Sea ice is frozen seawater.Because ice is less dense thanliquid water, sea ice floats on theocean's surface (as does fresh water ice, which has an even lower density). Sea ice covers about 7% of 

the Earth’s surface, or about 12% of the world’s oceans.[1][2] In the North,it is found in the Arctic Ocean, inareas just below it and in other coldoceans, seas and gulfs; in the Antarctic, it occurs in various areasaround Antarctica (the continent).Much of the world's sea ice isenclosed within the polar ice packsin the Earth's polar regions: the Arctic ice pack of the Arctic Oceanand the Antarctic ice pack of theSouthern Ocean. Polar packsundergo a significant yearly cyclingin surface extent (see Climatechange in the Arctic), a naturalprocess upon which depends the Arctic ecology, including the ocean'secosystems. Due to the action of winds, currents and temperaturefluctuations, sea ice is very dynamic,leading to a wide variety of ice typesand f eatures. Sea ice may becontrasted with icebergs, which arechunks of ice shelves or glaciers that

calve into the ocean. Depending onlocation, sea ice expanses may alsoincorporate icebergs.

Contents

1 Sea ice: General features

and dynamics

1.1 Fast ice versus

drift (or pack) ice

1.2 Classificationbased on age

1.2.1 New ice, nilas and young ice

1.2.2 First-year sea ice

1.2.3 Old sea ice

1.3 Driving forces

1.4 Deformation

1.5 Leads and polynyas

2 Formation of sea ice

3 Yearly freeze and melt cycle

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4 Monitoring and observations

5 Modelling

6 Ecology

7 Relationship to global warming and climate change

8 See also

8.1 Ecology

8.2 Geography/climatology

8.3 Ice types or features

8.4 Physics & chemistry

8.5 Applied sciences & engineering endeavours

9 References

10 Sea ice glossaries

11 External links

Sea ice: General features and dynamics

Sea ice does not simply grow and melt. During its lifespan, it is very dynamic. Due to the combined action of winds,

currents and air temperature fluctuations, sea ice expanses typically undergo a significant amount of deformation. Seaice is classified according to whether or not it is able to drift, and according to its age.

Fast ice versus drift (or pack) ice

Sea ice can be classified according to whether or not it is attached (or frozen) to the shoreline (or between shoals or togrounded icebergs). If attached, it is called landfast ice, or more often, fast ice (from fastened ). Alternatively, and unlikefast ice, drift ice occurs further offshore in very wide areas, and encompasses ice that is free to move with currents andwinds. The physical boundary between fast ice and drift ice is the fast ice boundary . The drift ice zone may be further divided into a shear zone, a marginal ice zone and a central pack .[3] Drift ice consists of floes, individual pieces of seaice 20 metres (66 ft) or more across. There are names for various floe sizes: small – 20 metres (66 ft) to 100 metres(330 ft); medium – 100 metres (330 ft) to 500 metres (1,600 ft); big – 500 metres (1,600 ft) to 2,000 metres (6,600 ft);vast – 2 kilometres (1.2 mi) to 10 kilometres (6.2 mi); and giant – more than 10 kilometres (6.2 mi). [4][5] The term pack

ice is used either as a synonym to drift ice,[4] or to designate drift ice zone in which the floes are densely packed. [4][5]

The overall sea ice cover is termed the ice canopy (from the perspective of submarine navigation).[5][6]

Classification based on age

 Another classification used by scientists to describe sea ice is based on age, that is, on its development stages. Thesstages are: new ice, nilas, young ice, first-year and old .[4][5][6]

New ice, nilas and young ice

New ice is a general term used for recently-frozen sea water that does not yet make up solid ice. It may consist of fraz

ice (plates or spicules of ice suspended in water), slush (water saturated snow), or  shuga (spongy white ice lumps a fecentimeters across). Other terms, such as grease ice and pancake ice, are used for ice crystal accumulations under the action of wind and waves.

Nilas designates a sea ice crust up to 10 centimetres (3.9 in) in thickness. It bends without breaking around waves andswells. Nilas can be further subdivided into dark nilas – up to 5 centimetres (2.0 in) in thickness and very dark, and lighnilas – over 5 centimetres (2.0 in) in thickness and lighter in color.

Young ice is a transition stage between nilas and first-year ice, and ranges in thickness from 10 centimetres (3.9 in) to30 centimetres (12 in), Young ice can be further subdivided into grey ice – 10 centimetres (3.9 in) to 15 centimetres(5.9 in) in thickness, and grey-white ice – 15 centimetres (5.9 in) to 30 centimetres (12 in) in thickness. Young ice is na flexible as nilas, but tends to break under wave action. In a compression regime, it will either raft (at the grey icestage) or ridge (at the grey-white ice stage).

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First-year sea ice

First-year sea ice is ice that is thicker than young ice but has no more than one year growth. In other words, it is icethat grows in the fall and winter (after it has gone through the new ice — nilas — young ice stages and grows further) bdoes not survive the spring and summer months (it melts away). The thickness of this ice typically ranges from 0.3metres (0.98 ft) to 2 metres (6.6 ft). [4][5][6] First-year ice may be further divided into thin (30 centimetres (0.98 ft) to 70centimetres (2.3 ft)), medium (70 centimetres (2.3 ft) to 120 centimetres (3.9 ft)) and thick  (>120 centimetres(3.9 ft)).[5][6]

Old sea ice

Old sea ice is sea ice that has survived at least one melting season (i.e. one summer). For this reason, this ice isgenerally thicker than first-year sea ice. Old ice is commonly divided into two types: second-year ice, which has surviveone melting season, and multiyear ice, which has survived more than one. (In some sources, [4] old ice is more than 2-years old.) Multi-year ice is much more common in the Arctic than it is in the Antarctic. [4][7] The reason for this is thatsea ice in the south drifts into warmer waters where it melts. In the Arctic, much of the sea ice is land-locked.

Driving forces

While fast ice is relatively stable (because it is attached to the shoreline or the seabed), drift (or pack) ice undergoesrelatively complex deformation processes that ultimately give rise to sea ice’s typically wide variety of landscapes. Win

is thought to be the main driving force along with ocean currents. [1][4] The Coriolis force and sea ice surface tilt have albeen invoked.[4] These driving forces induce a state of stress within the drift ice zone. An ice floe converging towardanother and pushing against it will generate a state of compression at the boundary between both. The ice cover mayalso undergo a state of tension, resulting in divergence and fissure opening. If two floes drift sideways past each other while remaining in contact, this will create a state of shear .

Deformation

Sea ice deformation results from the interaction between ice floes, as they are driven against each other. The end resumay be of three types of features:[5][6] 1) Rafted ice, when one piece is overriding another; 2) Pressure ridges, a line of broken ice forced downward (to make up the keel ) and upward (to make the sail ); and 3) Hummock , an hillock of brokeice that forms an uneven surface. A shear ridge is a pressure ridge that formed under shear – it tends to be more linear

than a ridge induced only by compression. [5][6] A new ridge is a recent feature — it is sharp-crested, with its sidesloping at an angle exceeding 40 degrees. In contrast, a weathered ridge is one with a rounded crest and with sidessloping at less than 40 degrees. [5][6]

Level ice is sea ice that has not been affected by deformation, and is therefore relatively flat.[5][6]

Leads and polynyas

Leads and polynyas are areas of open water that occur within sea ice expanses even though air temperatures are belofreezing, and provide a direct interaction between the ocean and the atmosphere, which is important for the wildlife.Leads are narrow and linear – they vary in width from meter to km scale. During the winter, the water in leads quicklyfreezes up. They are also used for navigation purposes – even when refrozen, the ice in leads is thinner, allowing

icebreakers access to an easier sail path, and submarines to surface more easily. Polynyas are more uniform in sizethan leads and are also larger – two types are recognized: 1) Sensible-heat polynyas, caused by the upwelling of warmer water and 2) Latent-heat polynyas, resulting from persistent winds from the coastline.

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 Aerial view showing anexpans e of drift iceoffshore Labrador (Eastern Canada)displaying floes of varioussizes loosely packed, withopen water in severalnetworks of leads. (Scalenot available.)

 

 Aerial view of the ChukchiSea between Chukotkaand Alaska, displaying apattern of leads. Much of the open water insidethose leads is alreadycovered by new ice(indicated by a slightlylighter blue color)(scalenot available).

 

 Aerial view showing anexpanse of drift ice insoutheastern Greenland,comprising loosely packedfloes of various s izes, witha lead developing in thecentre.(Scale notavailable.)

 

 Aerial view showing anexpanse of drift iceconsis ting mos tly of water.(Scale not available.)

 

Close-up view inside adrift ice zone: several

small rounded floes areseparated from each other by slus h or grease ice.(Bird at lower right for scale.)

 

Example of hummocky ice:an accumulation of ice

blocks, here about 20 to30 cm in thickness (with athin snow cover).

 

Field example of apressure ridge. Only the

sai l (the part of the ridgeabove the ice surface) isshown in this photograph

 – the keel is more difficultto document.

Formation of sea ice

Main article: Sea ice growth processes

Only the top layer of water needs to cool to the freezing point. Convection of the surface layer involves the top 100 – 15m, down to the pycnocline of increased density.

In calm water, the first sea ice to form on the surface is a skim of separate crystals which initially are in the form of tinydiscs, floating flat on the surface and of diameter less than 0.3 centimetres (0.12 in). Each disc has its c-axis verticaland grows outwards laterally. At a certain point such a disc shape becomes unstable, and the growing isolated crystaltake on a hexagonal, stellar form, with long fragile arms stretching out over the surface. These crystals also have their axis vertical. The dendritic arms are very fragile, and soon break off, leaving a mixture of discs and arm fragments. Withany kind of turbulence in the water, these fragments break up further into random-shaped small crystals which form asuspension of increasing density in the surface water, an ice type called frazil or grease ice. In quiet conditions the frazcrystals soon freeze together to form a continuous thin sheet of young ice; in its early stages, when it is still transpare— that is the ice called nilas. Once nilas has formed, a quite different growth process occurs, in which water freezes oto the bottom of the existing ice sheet, a process called congelation growth. This growth process yields first-year ice.

 

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Satellite image of sea ice forming near St.

Matthew Island in the Bering Sea.

Seasonal variation and annual decrease of 

 Arctic sea ice volume as estimated bymeasurement backed numerical modelling.[8

Volume of arctic sea ice over time using a

polar coordinate system draw method (timegoes counter clockwise; one cycle per 

year)

In rough water, fresh sea ice is formed by the cooling of the ocean as heat islost into the atmosphere. The uppermost layer of the ocean is supercooled toslightly below the freezing point, at which time tiny ice platelets (frazil ice)form. With time, this process leads to a mushy surface layer, known asgrease ice. Frazil ice formation may also be started by snowfall, rather thansupercooling. Waves and wind then act to compress these ice particles intolarger plates, of several meters in diameter, called pancake ice. These floaton the ocean surface, and collide with one another, forming upturned edges.In time, the pancake ice plates may themselves be rafted over one another or frozen together into a more solid ice cover, known as consolidated ice

pancake ice. Such ice has a very rough appearance on top and bottom.

If sufficient snow falls on sea ice to depress the freeboard below sea level,sea water will flow in and a layer of ice will form of mixed snow/sea water.This is particularly common around Antarctica.

Russian scientist Vladimir Vize (1886–1954) devoted his life to study the Arctic ice pack and developed the Scientific Prediction of Ice Conditions Theory , for which he was widely acclaimed inacademic circles. He applied this theory in the field in the Kara Sea, which led to the discovery of Vize Island.

 Yearly freeze and melt cycle

Sea ice freezes and melts due to a combination of factors, including the ageof the ice, air temperatures, and solar insolation. During the winter the area of the Arctic Ocean covered by sea ice increases, usually reaching a maximumextent during the month of March. The area covered in sea ice thendecreases, reaching its minimum extent in September most years. First-year ice melts more easily than older ice for two reasons: 1) First-year ice isthinner than older ice, since the process of congelation growth has had lesstime to operate; and 2) first-year ice is less permeable than older ice, sosummer meltwater tends to form deeper ponds on the first-year ice surfacethan on older ice, and deeper ponds mean lower albedo and thus greater solar energy capture.

Monitoring and observations

Main article: Measurement of sea ice

Changes in sea ice conditions are best demonstrated by the rate of meltingover time. A composite record of Arctic ice demonstrates that the floes’retreat began around 1900, experiencing more rapid melting beginning withinthe past 50 years. Satellite study of sea ice began in 1979, and became amuch more reliable measure of ice melt and polar climate change. Incomparison to the extended record, the sea-ice extent in the polar region bySeptember 2007 was only half the recorded mass that had been estimated toexist within the 1950–1970 period.[9]

The volume of ice hit an all-time low in September 2012, when the ice wasdetermined to cover only 24% of the Arctic Ocean, offsetting the previous lowof 29% in 2007. Future predictions cast that summer sea ice mightdisappear altogether as soon as 2020. [10] During the warmest years, like thewinter of 2005–2006, sea ice is observed to reach a winter maximum extentthat is smaller than in the years before or after. The summer minimum Arcticice extent for 2010 was the third lowest over the period of satelliteobservations of the polar ice.[11]

Modelling

 

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In order to gain a better understanding about the variability, numerical sea ice models are used to perform sensitivitystudies. The two main ingredients are the ice dynamics and the thermodynamical properties (see Sea ice emissivitymodelling, Sea ice growth processes and Sea ice thickness).

Many Global Climate Models (GCMs) have sea ice implemented in their numerical simulation scheme in order tocapture the Ice-albedo feedback correctly. Examples are:

The MIT General Circulation Model (MITgcm (http://mitgcm.org/)) is a global circulation model developed at

Massachusetts Institute of Technology (MIT) includes a package for sea-ice (MITgcm:seaice

(http://mitgcm.org/tag/sea-ice-modeling/)). The code is freely available there.The University Corporation for Atmospheric Research (UCAR) develops the Community Sea Ice Model (CSIM

(http://www.cesm.ucar.edu/models/ice-csim/)).

The Los Alamos National Laboratory has a project called Los Alamos Sea Ice Model (CICE

(http://climate.lanl.gov/Models/CICE)). CICE is open source and designed as s component of GCM, although it

provides a standalone mode.

The Finite-Element Sea-Ice Ocean Model (FESOM

(http://www.awi.de/en/research/research_divisions/climate_science/climate_dynamics/research_projects/couple

 _model_development_echam5_fesom/)) developed at Alfred Wegener Institute uses an unstructured grid.

The Coupled model intercomparison project (CMIP (http://cmip-pcmdi.llnl.gov/)) offers a standard protocol for studying

the output of coupled atmosphere-ocean general circulation models. The coupling takes place at the atmosphere-oceainterface where the sea ice may occur.

In addition to global modeling, various regional models deal with sea ice. Regional models are employed for seasonaforecasting experiments and for process studies.

Ecology

Main article: Sympagic ecology 

Sea ice is part of the Earth's biosphere. When sea water freezes, the ice is riddled with brine-filled channels whichsustain sympagic organisms such as bacteria, algae, copepods and annelids, which in turn provide food for animals

such as krill and specialised fish like the Bald notothen, fed upon in turn by larger animals such as Emperor penguinsand Minke whales.[12]

 A decline of seasonal sea ice puts the survival of Arctic species such as ringed seals and polar bears at risk. [13][14][15

Relationship to global warming and climate change

Sea ice provides an ecosystem for various polar species, particularly the polar bear, whose environment is beingthreatened as global warming causes the ice to melt a bit more as the Earth’s temperature gets warmer. Furthermore,the sea ice itself functions to help keep polar climates cool, since the ice exists in expansive enough amounts tomaintain a cold environment. At this, sea ice’s relationship with global warming is cyclical; the ice helps to maintaincool climates, but as the global temperature increases, the ice melts, and is less effective in keeping those climatescold. The bright, shiny surface of the ice also serves a role in maintaining cooler polar temperatures by reflecting muchof the sunlight that hits it back into space. As the sea ice melts, its surface area shrinks, diminishing the size of thereflective surface and therefore causing the earth to absorb more of the sun’s heat. Though the size of the ice floes isaffected by the seasons, even a small change in global temperature can greatly affect the amount of sea ice, and due tthe shrinking reflective surface that keeps the ocean cool, this sparks a cycle of ice shrinking and temperatureswarming. As a result, the polar regions are the most susceptible places to climate change on the planet. [4]

Furthermore, sea ice affects the movement of ocean waters. In the freezing process, much of the salt in ocean water issqueezed out of the frozen crystal formations, though some remains frozen in the ice. This salt becomes trappedbeneath the sea ice, creating a higher concentration of salt in the water beneath ice floes. This concentration of saltcontributes to the salinated water’s density, and this cold, denser water sinks to the bottom of the ocean. This coldwater moves along the ocean floor towards the equator, while warmer water on the ocean surface moves in the directioof the poles. This is referred to as “conveyor belt motion”, and is regularly occurring process.[4]

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Change in extent of the Arctic Sea ice betweenMarch and September.

 

Sea ice off Baffin Island.

 

Sea ice imitates theshoreline along theKamchatka Peninsula.

 

Clear view of the AntarcticPeninsula, the Larsen IceShelf, and the sea icecovered waters around theregion.

See also

Ecology

 Antarctic ecozone

 Arctic ecology

 Arctic fox

 Arctic sea ice ecology and history

Ice algae

Penguins

Polar bear 

Seals

Geography/climatology

 Antarctic

 Antarctica

 Arctic

 Arctic Ocean

 Arctic Sea

Climate change in the Arctic

Cryosphere

Polar ice cap

Polar ice packs

Polar region

Ice types or features

 Anchor ice

Congelation ice

Drift ice

Fast ice

Finger rafting

Frazil ice

Grease ice

Iceberg

Lead (sea ice)

Pancake ice

Polynya

Pressure ridge (ice)

Rotten ice

Seabed gouging by ice

Slush

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Physics & chemistry

Decline of sea ice

Ice

Ice cr ystals

Ice Ih

Sea ice

Sea ice growth processes

Seawater 

Applied sciences & engineering endeavours

Drif t ice station

Drif t station

Ice class

Icebr eaker 

Measurement of sea ice

Sea ice concentration

Sea ice emissivity modelling

Sea ice thickness

Zhubov scale

References

1. ^ a b NOAA Sea Ice essay

2. ^ Weeks, Willy F. (2010). On Sea Ice (http://books.google.com/books?id=9S55O6WzuL8C&pg=PA2). University of 

 Alaska Press . p. 2. ISBN 978-1-60223-101-6.

3. ^ Leppr   anta, Matti (2005). The Drift Of Sea Ice (http://books.google.com/books?id=xJwub7E6VDcC). Springer. ISBN 97

3-540-40881-9.

4. ^ a b c  d  e f  g  h i   j  k NSIDC All About Sea Ice

5. ^ a b c  d  e f  g  h i   j Environment Canada Ice Glossary

6. ^ a b c  d  e f  g  h i WMO Sea-Ice Nomenclature7. ^ Wadhams , P. (2000). Ice in the Ocean. CRC Press . ISBN 978-90-5699-296-5.

8. ^ Zhang, Jinlun; Rothrock, D.A. (May 2003). "Modeling global s ea ice with a thickness and enthalpy distribution model

gener alized curvilinear coordinates" (http://journals.ametsoc.org/doi/abs/10.1175/1520-

0493%282003%29131%3C0845%3AMGSIWA%3E2.0.CO%3B2). Mon. Wea. Rev. 131 (5): 845–861.

Bibcode:2003MWRv..131..845Z (http://adsabs.harvard.edu/abs /2003MWRv..131..845Z). doi:10.1175/1520-

0493(2003)131<0845:MGSIWA>2.0.CO;2 (http://dx.doi.org/10.1175%2F1520-

0493%282003%29131%3C0845%3AMGSIWA%3E2.0.CO%3B2).

9. ^ Polyak, Leonid; Richard B. Alley, John T. Andrews , Julie Brigham-Grette, Thomas M. Cronin, Dennis A. Darby, Arthur

Dyke, Joan J. Fitzpatrick, Svend Funder, Marika Holland, Anne E. Jennings, Gifford H. Miller, Matt O’Regan, James

Savelle, Mark Serreze, Kris ten St. John, James W.C. White, Eric Wolff (3 February 2010). "History of sea ice in the Arctic(http://www.geo.umass .edu/faculty/jbg/Pubs/Polyak%20etal%20seaice%20QSR10%20inpress .pdf) (PDF). Quaternary

Science Reviews: 2–17. doi:10.1016/+j.quascirev.2010.02.010

(http://dx.doi.org/10.1016%2F%2Bj.quascirev.2010.02.010).

10. ^ Gillis, Jus tin (19 Sept 2012). "Ending Its Summer Melt, Arctic Sea Ice Sets a New Low That Leads to Warnings"

(http://www.nytimes.com/2012/09/20/science/earth/arctic-sea-ice-stops-melting-but-new-record-low-is-set.html?_r=0)

The N ew York Times. Retrieved 5 Oct 2012.

11. ^ Scott, Michon. "Arctic Sea Ice Minim um for 2010" (http://earthobservatory.nasa.gov/IOTD/view.php?id=46282). NASA

Earth Observatory. Retrieved 6 October 2010.

12. ^ "Sea Ice Ecology" (http://www.acecrc.sipex.aq/access/page/?page=d664da82-b244-102a-8ea7-0019b9ea7c60).

 

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Text is available under the Creative Commons Attr ibution-ShareAlike License; additional terms may apply.By using this site, you agree to the Terms of Use and Privacy Policy.

Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-prof it organization.

. . . .

13. ^ Bar ber, D.G.; Iacozza, J. (March 2004). "Historical analysis of sea ice conditions in M'Clintock Channel and the Gulf o

Boothia, Nunavut: implications for ringed s eal and polar bear habitat" (http://goliath.ecnext.com/coms 2/gi_0199-

263435/Historical-analysis-of-sea-ice.html). Arctic  57 (1): 1–14. JSTOR 40512590 (//www.jstor.org/stable/40512590).

14. ^ Stir ling, I.; Lunn, N.J.; Iacozza, J.; Ellio tt, C.; Obbard, M. (March 2004). "Polar bear dis tribution and abundance on the

southwestern Hudson Bay coast during open water season, in relation to population trends and annual ice patterns".

 Arct i c  57 (1): 15–26. JSTOR 40512591 (//www.jstor.org/stable/40512591).

15. ^ Stir ling, I.; Parkinson, C.L. (September 2006). "Possible effects of climate warming on s elected populations of polar 

bear s (Ursus maritimus) in the Canadian Arctic"(http://www1.nasa.gov/pdf/157360main_StirlingParkinson2006_Arctic59-3-261.pdf) (PDF). Arctic  59 (3): 261–275.

JSTOR 40512813 (//www.jstor.org/stable/40512813).

Rothrock, D.A.; Zhang, J. (2005). "Arctic Ocean Sea Ice Volume: What Explains Its Recent Depletion?". J. Geophys. Res

110 (C1): C01002. Bibcode:2005JGRC..11001002R (http://adsabs.harvard.edu/abs/2005JGRC..11001002R).

doi:10.1029/2004JC002282 (http://dx.doi.org/10.1029%2F2004JC002282).

"How Does Arctic Sea Ice Form and Decay?" (http://www.arctic.noaa.gov/essay_wadhams.html). NOAA Arctic theme

 pag e. Retrieved 25 April 2005.

"All About Sea Ice" (http://nsidc.org/cryosphere/seaice/). National Snow and Ice Data Center, University of Colorado,

Boulder.Vinnikov, K.Y.; Cavalieri, D.J.; Parkinson, C.L. (March 2006). "A model assessment of satellite observed trends in polar

sea ice extents" (http://onlinelibrary.wiley.com/doi/10.1029/2005GL025282/abstract). Geophys. Res. Lett. 33 (5): L0570

Bibcode:2006GeoRL..33.5704V (http://adsabs.harvard.edu/abs/2006GeoRL..33.5704V). doi:10.1029/2005GL025282

(http://dx.doi.org/10.1029%2F2005GL025282).

Sea ice glossaries

"Cr yosphere Glossary" (http://nsidc.org/cgi-bin/words/glossary.pl). National Snow and Ice Data Center, Univers

of Colorado, Boulder.

"Ice Glossary" (http://www.ec.gc.ca/glaces-ice/default.asp?lang=En&n=501D72C1-1). Environment Canada.

"WMO Sea-Ice Nomenclature" (http://www.aari.nw.ru/gdsidb/XML/volume1.php?lang1=0&lang2=1&arrange=1).

World Meteorological Organization. WMO/OMM/ВМО — No.259 • Edition 1970–2004.

External links

Cryosphere today: Current sea ice conditions from the University of Illinois

(http://arctic.atmos.uiuc.edu/cryosphere/)

Daily  Advanced Microwave Scanning Radiometer 2 sea ice maps from the University of Bremen

(http://www.iup.uni-bremen.de:8084/amsr2/)

"National Snow and Ice Data Center" (http://nsidc.org). University of Colorado, Boulder.

Sea Ice Index (http://nsidc.org/data/seaice_index/)Global Sea Ice Extent and Concentration: What sensors on satellites are telling us about sea ice

(http://nsidc.org/sotc/sea_ice.html)

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Categories: Sea ice Aquatic ecology Earth phenomena Bodies of ice

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10/28/13 Sea ice - Wikipedia, the free encyclopedia

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